1. Technical Field of the Invention
This invention relates to the field of fiber optic cables and more particularly to a fiber optic cable having a detectable binder that enables a binder laylength to be measured during the cable manufacturing process.
2. Description of the Related Art
Multi-fiber cables are widely used for communication purposes including telecommunication and data transmission. In particular, fiber optic cables are commonly incorporated into communication networks thus enabling the communication network to operate with wide bandwidth and low noise operation.
As would be understood by one skilled in the art, fiber optic cables customarily include a strength member and an protective outer jacket. Buffer tubes, housing the optic fibers, are positioned around the strength member in a variety of configurations thereby providing an assortment of fiber counts depending on the chosen configuration. These individual fibers are usually grouped into a variety of fiber optic bundles. A binder is then wrapped around the fiber optic bundles or the buffer tube itself. The core, comprising the buffer tubes configured around the strength member, is then encased by a plastic outer jacket thereby forming a fiber optic cable.
Binders consist of a tape-like material and are used in a fiber optic cables to bind cable components together. As stated above, one or more binders may be stranded around a cable component, such as a buffer tube, thus providing additional strength in to the cable components. Furthermore, binders may be stranded around groups of optic fibers to form fiber optic bundles.
Binders also help couple buffer tubes to the strength member in addition to keeping the stranded loose buffer tubes from moving during fluctuations in temperature. The laylength of the binder itself is critical and differs with each fiber optic cable design. For example, if a particular cable design is sensitive, the binder laylength must be properly adjusted (tightened or loosened) to protect the buffer tube from movement resulting from temperature fluctuations.
Color is commonly used in the fiber optic cable industry to aid in the identification of individual optic fibers and buffer tubes. Industry standards define the colors used to identify particular buffer tubes or optic fiber. Color coding the buffer tube allows technicians to easily distinguish between different optical fibers.
Manufacturing fiber optic cables has increasingly developed into an automated process. Measuring the length of the binder material necessary for a particular cable design, however, is still a manual process. Traditionally, the binder is manually measured using a ruler or a tape measure. The binder laylength is then calculated by measuring the distance from a first peak on the bound core to a second peak on the bound core, or from one binder center to the next binder center. Manually measuring the binder laylength is therefore a trial and error process. Often, cable portions must be scrapped until an acceptable measurement is obtained for the particular cable design.
This manual process can result in frequent human error and a steep increase in operating cost due to system downtime and scrap. An incorrect binder laylength can also result in a cable that is susceptible to thermal failure due to optical unit movement. Accordingly, an automated process for measuring the length of a binder is essential.